1. Field of the Invention
The present invention relates to a guide sheath used under guidance of an internal introduction device, and a medical system including the guide sheath.
2. Description of Related Art
In the related art, a catheter tube configured to be inserted into a body cavity, a blood vessel, or the like, and inject liquid medicine or discharge body fluid is used. Such a catheter tube is disclosed in, for example, Japanese Unexamined Patent Application, First Publication No. H08-57035. The catheter tube is formed by continuously varying degrees of cross-linking of a synthetic resin in a longitudinal direction.
In manufacturing the catheter tube, a synthetic resin sensitive to cross-linking treatment by radiation or the like and a synthetic resin insensitive thereto are combined. Then, a tube melted and extruded while continuously varying a mixing ratio of these synthetic resins is cross-linked using radiation of a β ray or the like. As the catheter tube is configured as described above, damage to organs can be prevented by a soft distal portion of the catheter tube while maintaining torque controllability and pushability by a hard proximal portion thereof.
In a treatment tool for an endoscope (hereinafter, simply referred to as a “treatment tool”) disclosed in Japanese Patent No. 4624483, a cross-linked section is formed by performing cross-linking treatment on a sheath formed of a thermoplastic resin. The cross-linked section generally has good heat resistance and physical strength. For this reason, for example, when a treatment unit heated to a high temperature by a high frequency current comes in contact with a sheath or when the treatment unit compresses the sheath upon pulling the treatment unit thereinto, melting or deformation of the sheath can be prevented.
Meanwhile, when the treatment tool is inserted into an introduction channel formed in the endoscope (an internal introduction device) and used, a distal end of a guide sheath is fixed while protruding from a distal end of the introduction channel to a predetermined position, and the treatment tool is inserted into the guide sheath. According to the above-mentioned procedure, the distal end of the treatment tool can be easily positioned when the treatment tool is changed from the introduction channel.